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A Facile Two‐Step Route to Branched Polyisoprenes via AB n ‐Macromonomers
Author(s) -
LópezVillanueva FranciscoJavier,
Wurm Frederik,
Kilbinger Andreas F. M.,
Frey Holger
Publication year - 2007
Publication title -
macromolecular rapid communications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.348
H-Index - 154
eISSN - 1521-3927
pISSN - 1022-1336
DOI - 10.1002/marc.200600782
Subject(s) - isoprene , macromonomer , polymer chemistry , dispersity , monomer , polymerization , polymer , hydrosilylation , anionic addition polymerization , living anionic polymerization , materials science , chemistry , polymer science , copolymer , organic chemistry , catalysis
A facile two‐step synthesis for branched poly(isoprene)s (PI) based on polyaddition of AB n ‐type macromonomers is described. The synthesis of the macromonomers was achieved by anionic polymerization of isoprene and subsequent end‐capping of the polymers by addition of chlorodimethylsilane to the living carbanions. This led to PI‐based macromonomers with narrow polydispersity ( $\overline M _{\rm w}$ / $\overline M _{\rm n}$ < 1.15) and molecular weights in the range of 1 700 – 22 100 g · mol −1 . Synthesis of the branched polymers was carried out by a hydrosilylation‐based polymerization of the macromonomers. Characterization via SEC, SEC‐MALLS, coupled SEC‐viscosimetry and 1 H‐NMR‐spectroscopy supported the formation of branched structures. Interestingly, these branched polymers exhibited α ‐values that were similar to those reported for hyperbranched polymers based on AB 2 ‐monomers.